The miniature tomato (Solanum lycopersicum) cultivar Micro-Tom (MT) has become an important platform to investigate plant-pathogen interactions. In the case of the witches' broom disease of Theobroma cacao (cacao), the existence of Moniliophthora perniciosa isolates pathogenic to Solanaceae (S-biotype) may enable the use of MT to circumvent limitations of the cacao host, whereas the availability of a non-infective cacao C-biotype allows the evaluation of contrasting responses of MT. Infection of MT by the S-biotype led to stem swelling and axillary shoot growth to form broom-like symptoms similar to the biotrophic phase in cacao, but the infected tissues did not progress to necrosis. Conversely, inoculation with the C-biotype did not cause typical symptoms, but reduced plant height, appearing as a non-host interaction. Histopathological characterization of the S-biotype infection of MT by light and electron microscopy indicated limited germ tube penetration, preferentially through wounds at the base of trichomes or actively through the epidermis. No intracellular mycelium was observed, corroborating the lack of the necrotrophic stage of the pathogen. The analysis of gene expression during the interaction between the S-or C-biotype with MT indicated that expression of plant defence-associated genes differs for kinetics and intensity between a compatible or incompatible M. perniciosa-MT interaction. The pattern of spore germination and low rate of mycelia penetration suggests that the S-biotype is not a fully adapted tomato pathogen, but possibly a case of broken non-host resistance, and evidence suggests the occurrence of a non-host MT response against the C-biotype.

A long-term study was conducted to evaluate Piracicaba River water (São Paulo state, Brazil) using different methodologies and organisms. During 1 year (February 2011 to January 2012), water samples were collected monthly at six different locations and exposed under laboratory conditions to the microcrustaceans Ceriodaphnia dubia and Ceriodaphnia silvestrii for 7 days and to the fish Danio rerio for 4 days to evaluate effects on reproduction and on gill morphology, respectively. Physical-chemical parameters of the water were also measured. Physical-chemical characteristics demonstrated decreasing water quality from upstream to downstream of the river. Effects on the reproduction of C. dubia and C. silvestrii were observed in 3 months (February and March 2011 and January 2012) and occurred in samples collected close to industrialized cities like Americana and Piracicaba. Evaluation of the gills showed normal function of the organ during all months, except in February, September, and October for some locations.

Floral colour change is a widespread phenomenon in angiosperms, but poorly understood from the genetic and chemical point of view. This article investigates this phenomenon in Pleroma raddianum, a Brazilian endemic species whose flowers change from white to purple. To this end, flavonoid compounds and their biosynthetic gene expression were profiled. By using accurate techniques (Ultra Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UPLC-HRMS)), thirty phenolic compounds were quantified. Five key genes of the flavonoid biosynthetic pathway were partially cloned, sequenced, and the mRNA levels were analysed (RT-qPCR) during flower development. Primary metabolism was also investigated by gas chromatography coupled to mass spectrometry (GC-EIMS), where carbohydrates and organic acids were identified. Collectively, the obtained results suggest that the flower colour change in P. raddianum is determined by petunidin and malvidin whose accumulation coincides with the transcriptional upregulation of early and late biosynthetic genes of the flavonoid pathway, mainly CHS and ANS, respectively. An alteration in sugars, organic acids and phenolic co-pigments is observed together with the colour change. Additionally, an increment in the content of Fe3+ ions in the petals, from the pink to purple stage, seemed to influence the saturation of the colour.

Introduction In 2002, the Surviving Sepsis Campaign defi ned a strategy that aimed to reduce the high mortality due to sepsis. One point of this strategy was a recommendation to recognize that sepsis is a frequent cause of death and high economic costs in the pediatric intensive care unit. Knowledge of the disease is the fi rst step to impact it. There are few studies on pediatric sepsis epidemiology in the world and none in Colombia. Hypothesis The epidemiological features of Colombian children are diff erent from other countries. Methods We constructed a website where 14 intensive care units across the country reported in a prospective way the epidemiological features of children with sepsis using an electronic process [1]. We asked for sociodemographics, microbiological data, sepsis classifi cation, complications, and outcome. Results We collected 253 patients from March to May 2009. Fifty-fi ve percent of the cases were male and 45% were female; 53% were less than 1 year old. A total of 67.2% came from urban areas and 33% came from rural villages. Eighty-fi ve percent were very poor (score 1 and 2 over 6 used in Colombia as socioeconomic classifi cation). Forty-fi ve percent have governmentsupported insurance. In total, 23.72% of the population presented with sepsis; 30.04% with severe sepsis; and 46.5% with septic shock. The infection origin was respiratory in 54.55%, followed by abdominal in 17.39%. In 50.2% no cause was identifi ed. A total of 75.1% required mechanical ventilation. The mortality rate was 20.4%. Conclusions Sepsis, severe sepsis, or septic shock is a common diagnosis in Colombian intensive care units. The majority of pediatric patients are 2 years or younger and from the poorest communities. It aff ected males more. In the majority, the process starts in the respiratory system. We had diffi culty identifying the cause. The disease causes high mortality and cost for a developing society. We need a complete survey to fi nd a correct approach to the problem. Reference 1. Sepsis en Columbia [www.sepsisencolombia.com] P2 Randomized controlled trials are not designed to prove the safety of third-generation hydroxyethyl starch for resuscitation: results from a systematic review

Sucrose metabolism is of high importance for most plant species, both as the main source of carbon and via signaling mechanisms that have been proposed for this molecule. Two cleaving enzymes channel sucrose into sink metabolism; sucrose synthases (SUS) and invertases (INV), which are localized in different subcellular compartments. Although acid soluble and insoluble invertases have been largely investigated, studies on the role of neutral invertases (A/N-INV) have lagged behind. Here, we identified a tomato A/N-INV encoding gene (NI6) co-localizing with a previously reported pathway QTL largely affecting primary carbon metabolism in tomato. Of the eight A/N-INV genes identified in the tomato genome, NI6 mRNA is present in all organs, but its expression was higher in sink tissues (mainly roots and fruits). A NI6-GFP fusion protein was found in the cytosol of mesophyll cells. Tomato NI6-silenced plants showed impaired growth phenotypes, delayed flowering and dramatic reduction in the fruit set. Global gene expression and metabolite profile analyses of these plants revealed that NI6 is not only essential for sugar metabolism but also plays a signaling role in stress adaptation. Gene-metabolite network analyses allowed identification of major hubs, whose expression patterns were greatly affected by NI6 silencing, within the signaling cascade that coordinates carbohydrate metabolism with growth and development in tomato.

SummaryThe study of crop diversification has focussed mainly on the genetic changes underlying traits favoured by humans. However, the passage from natural habitats to agronomic settings probably operated changes beyond those comprising the classical domestication syndrome. A deeper understanding of these traits and their genetic signature would be valuable to inform conventional crop breeding and de novo domestication of crop wild relatives. Heterobaric leaves have bundle sheath extensions (BSEs) that compartmentalise the sub-stomatal cavity whereas homobaric leaves do not; BSE development is known to be controlled by the OBSCURAVENOSA (OBV) locus and the obv mutant lacks BSEs whereas leaves carrying the wild type allele have BSEs. Here we identify the OBV gene and the causative mutation, a non-synonymous amino acid change. This mutation exists as a rare balanced polymorphism in the natural range of wild tomatoes, but has increased in frequency in domesticated tomatoes suggesting that the latter diversified into heterobaric and homobaric leaf types. The mutation disrupts a C2H2 zinc finger motif in the OBV protein, resulting in the absence of BSEs in leaves and here we show that this and other pleiotropic effects, including changes in leaf insertion angle, leaf margin serration, minor vein density and fruit shape, are controlled by OBV via changes in auxin signalling. Loss of function of the transcriptional regulator AUXIN RESPONSE FACTOR (ARF4) also results in defective BSE development, revealing an additional component of a novel genetic module controlling aspects of leaf development important for ecological adaptation and subject to breeding selections.One sentence summaryDistribution of heterobaric and homobaric leaves is controlled by natural variation in an auxin-related transcription factor

Heterobaric leaves have bundle sheath extensions (BSEs) that compartmentalize the sub-stomatal cavity, whereas homobaric leaves do not. In tomato (Solanum lycopersicum), BSE development is controlled by the OBSCURAVENOSA (OBV) locus. The obv mutant lacks BSEs, whereas leaves carrying the wild-type allele have BSEs. Here, we identify the obv gene and the causative mutation, a non-synonymous amino acid change. This mutation exists as a rare polymorphism in the natural range of wild tomatoes but has increased in frequency in domesticated tomatoes, suggesting that the latter diversified into heterobaric and homobaric leaf types. The mutation disrupts a C2H2 zinc finger motif in the OBV protein, resulting in the absence of BSEs in leaves and alterations to leaf function: Photosynthetic assimilation rate and leaf hydraulic conductance are both reduced in obv. Here, we show that both of these and other pleiotropic effects, including changes in leaf insertion angle, leaf margin serration, minor vein density, and fruit shape, are controlled by OBV via changes in auxin signalling. Loss of function of the transcriptional regulator AUXIN RESPONSE FACTOR 4 (ARF4) also results in defective BSE development, revealing an additional component of a genetic module controlling aspects of leaf development important for ecological adaptation and for breeding selection.

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